It is often desirable to capture a digital image of an ocular feature for many medical or veterinary purposes. As used herein, an ocular feature is defined as any anatomical structure associated with an animal or human eye. For example, an ocular feature may include, but is not limited to, the retina, optic nerve or the retinal vascularization of an animal or human subject's eye. Digital images of an ocular feature may be useful to assist with the diagnosis of a condition, abnormality, disease, or healthy eye. Similarly a series of images of an ocular feature taken over time may be utilized to track the progression of a condition, abnormality, disease or healthy eye.
The capture of digital images of ocular features may be both difficult and time consuming, particularly when the subject of examination is unable to keep from moving their eye for any reason. For example, animals are typically unwilling or unable to hold their eyes still for veterinary examination. Babies and children may find it impossible or difficult to hold their eyes still during an examination as well. Premature babies have an increased risk of developing retinopathy. Because of this, multiple retinal eye exams are routinely performed on premature babies during the first several months after birth. Typically, a retinal examination is a very challenging and invasive procedure to perform on a newborn since babies generally move their eyes around very rapidly making it difficult for an ophthalmologist to get a clear view of the retina. In addition, the field of view of many optical fundus cameras is relatively small when compared to the entire inner structure of any eye. Thus, it is very difficult for an examining ophthalmologist to capture a suitable image that shows a particular ocular feature or region of interest within the eye to aid in the diagnosis of a condition, disease or abnormality as described above.
It is also often desirable to capture a high quality digital image of an ocular feature without the use of medication to fully dilate the patient's pupil. For example, it is often deemed prudent to avoid using medication to dilate the patient's pupil when the patient is an animal or a baby. High quality ocular imaging, however, requires a significant amount of light to fully illuminate the ocular feature of interest. The application of sufficient illumination to a patient's non-medicated eye for high resolution imaging will typically cause a rapid pupil response significantly reducing the area through which interior ocular features may be viewed and thus limiting the available field of view. Pupil constriction will also dramatically reduce the penetration of the light used to image the feature.
The present embodiments are directed toward overcoming one or more of the problems noted above.